I entered your medications into the interactions checker and the results did not include any problems with the vitamins and the other medications you take.
However, there is an interaction between the Savella and the Effexor which involves the possibility of serotonin syndrome. The symptoms of serotonin syndrome may include mental status changes such as irritability, altered consciousness, confusion, hallucinations, and coma; autonomic dysfunction such as tachycardia, hyperthermia, diaphoresis, shivering, blood pressure lability, and mydriasis; neuromuscular abnormalities such as hyperreflexia, myoclonus, tremor, rigidity, and ataxia; and gastrointestinal symptoms such as abdominal cramping, nausea, vomiting, and diarrhea.
This a rare condition and is probably not a problem if the meds are prescribed by the same doctor or all your doctors know what you are taking, but just thought you should know.
The only other interactions involve the tamoxifen and food and the savella and alcohol. You should not eat soy containing products while on tamoxifen. You should not consume alcohol in excess with the savella due to the possibilty of increased liver damage.
Maybe that was more than you wanted to know but I thought that I should share everything I discovered.